X-ray imaging apparatus and method of operating the same

ABSTRACT

An X-ray imaging apparatus and a method of operating the X-ray imaging method are provided. The X-ray imaging apparatus includes a first panel configured to contact an object; an X-ray generator configured to maintain a uniform distance with the first panel and configured to generate an X-ray; a second panel facing the first panel and configured to contact the object; and an X-ray detector configured to detect the X-ray transmitted to the object.

RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2013-0073967, filed on Jun. 26, 2013, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND

1. Field

Apparatuses and methods consistent with the exemplary embodiments relateto an X-ray imaging apparatus using an X-ray and a method of operatingthe X-ray imaging apparatus.

2. Description of the Related Art

X-rays are used in performing non-destructive testing, structural andphysical properties testing, image diagnosis, security inspection, andthe like in the fields of industry, science, medical treatment, etc.Generally, an imaging system using X-rays for such purposes includes anX-ray generator for radiating an X-ray and an X-ray detector fordetecting X-rays that have passed through an object.

The X-ray detector is being rapidly converted from a film method to adigital method, whereas the X-ray generator uses an electron generationdevice using a tungsten filament type cathode. Thus, a single electrongeneration device is mounted in a single X-ray imaging apparatus. TheX-ray detector is generally implemented as a flat panel type, which isproblematic since there is a distance between the X-ray generator andthe object when obtaining an image from the single electron generationdevice. Furthermore, the object needs to be imaged from a single X-raygenerator, which makes it difficult to select and image a specific partof the object.

SUMMARY

An exemplary embodiment includes an X-ray imaging apparatus including aflat panel type X-ray generator and a method of operating the X-rayimaging apparatus.

An exemplary embodiment includes an X-ray imaging apparatus capable ofobtaining a tomography image and a method of operating the X-ray imagingapparatus.

An exemplary embodiment includes an X-ray generator capable of adjustinga radiation angle of an X-ray, an X-ray imaging apparatus including theX-ray generator, and a method of operating the X-ray imaging apparatus.

An exemplary embodiment includes an X-ray imaging apparatus operable todetect an object and radiate an X-ray only to the object and a method ofoperating the X-ray imaging apparatus.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented exemplary embodiments.

According to an exemplary embodiment, an X-ray imaging apparatusincludes: a first panel configured to contact an object; an X-raygenerator configured to maintain a uniform distance with the first paneland configured to generate an X-ray and transmit the X-ray to theobject; a second panel facing the first panel and configured to contactthe object; and an X-ray detector configured to detect the X-raytransmitted by the X-ray generator to the object.

The X-ray generator may is configured to move towards or away from theobject.

A first surface of the first panel is configured to contact the objectand a second surface facing the first surface is configured to contactthe X-ray generator.

The X-ray generator and the first panel may be integrated.

A first surface of the second panel is configured to contact the objectand a second surface facing the first surface is configured to contactthe X-ray detector.

At least one of the first panel and the second panel may press theobject.

When an X-ray generation area of the X-ray generator is smaller than atest area of the object, the X-ray generator is configured to move so asto transmit an X-ray to an entire test area of the object.

The X-ray generator is configured to radiate the X-ray in a first areaof the object and configured to move so as to radiate the X-ray in asecond area of the object.

The X-ray generator is configured to move horizontally along the firstpanel.

When an X-ray detection area of the X-ray detector is smaller than atest area of the object, the X-ray detector is configured to move so asto detect an X-ray that was transmitted to an entire test area of theobject.

The X-ray detector is configured to detect the X-ray that wastransmitted to a first area of the object and move to detect the X-raythat was transmitted to a second area of the object.

The X-ray detector is configured to move horizontally along the secondpanel.

The X-ray imaging apparatus may further include: a gantry including thefirst panel, the X-ray generator, the second panel, and the X-raydetector.

The X-ray generator may include a plurality of X-ray sub-generatorsarranged in one dimension or in two dimensions.

The X-ray generator may change a radiation angle of an X-raytransmission according to a location of the object.

The X-ray imaging apparatus may further include: a sensor configured tosense the object, wherein a partial region of the X-ray generatorcorresponding to a location of the object generates the X-ray.

According to an exemplary embodiment, an X-ray imaging method includes:pressing an object located between a first panel and a second panel byusing at least one of the first panel and the second panel; generatingan X-ray by an X-ray generator located a uniform distance from the firstpanel; transmitting by the X-ray generator the generated X-ray to theobject; and detecting by the X-ray detector the X-ray transmitted to theobject.

The X-ray generator is configured to move towards and away from theobject.

When an X-ray generation area of the X-ray generator is smaller than atest area of the object, the X-ray generator may move along the firstpanel to radiate an X-ray in the entire test area of the object.

When an X-ray detection area of the X-ray detector is smaller than atest area of the object, the X-ray detector may move along the secondpanel to detect an X-ray that was transmitted to the entire test area ofthe object.

According to an exemplary embodiment, an X-ray imaging apparatusincludes: a first panel configured to contact an object; an X-raygenerator which is integrated with the first panel in order to maintaina uniform distance with the first panel and configured to generate anX-ray and transmit the X-ray to the object; a second panel facing thefirst panel and configured to contact the object; and an X-ray detectorconfigured to detect the X-ray transmitted by the X-ray generator to theobject.

The X-ray generator comprises a plurality of sub-generators and each ofthe plurality of sub-generators are configured to generate an X-ray.

Each of the plurality of sub-generators comprise a plurality of sensorswhich sense the object.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the exemplary embodiments,taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic perspective view of an X-ray imaging apparatusaccording to an exemplary embodiment;

FIGS. 2A and 2B are schematic diagrams of X-ray generators including aplurality of X-ray sub-generators according to an exemplary embodiment;

FIGS. 3A to 3D are schematic diagrams of X-ray sub-generators accordingto exemplary embodiments;

FIG. 4 illustrates an electron emission device including a gateelectrode, according to an exemplary embodiment;

FIGS. 5A to 5G illustrate anode electrodes having irregular thicknesses,according to exemplary embodiments;

FIG. 6 illustrates an anode electrode having a uniform thickness,according to an exemplary embodiment;

FIG. 7 illustrates an anode electrode formed of different materials,according to an exemplary embodiment;

FIGS. 8A and 8B illustrate anode electrodes formed of differentmaterials, according to exemplary embodiments;

FIGS. 9A to 9C illustrate an X-ray generator generating an X-ray of ashort wavelength or an X-ray of a plurality of wavelength bandsaccording to exemplary embodiments;

FIGS. 10A and 10B schematically illustrate X-ray detectors that may beapplied to an X-ray detector of FIG. 1;

FIGS. 11A and 11B are diagrams for explaining an X-ray imaging methodwhen an X-ray generation area is smaller than a test area of an objectaccording to an exemplary embodiment;

FIGS. 12A and 12B are diagrams for explaining an X-ray imaging methodwhen an X-ray detection area is smaller than a test area of an objectaccording to an exemplary embodiment;

FIGS. 13A through 13C are diagrams for explaining an X-ray imagingmethod so as to acquire a tomography image according to an exemplaryembodiment;

FIGS. 14A through 14C are diagrams for explaining an X-ray imagingmethod so as to acquire a tomography image according to anotherexemplary embodiment;

FIG. 15 is a schematic diagram of an X-ray generator according to anexemplary embodiment;

FIGS. 16A through 16C are diagrams for explaining an X-ray imagingmethod so as to acquire a tomography image according to anotherexemplary embodiment;

FIG. 17 is a schematic diagram of an X-ray generator used to acquire atomography image according to an exemplary embodiment;

FIGS. 18A and 18B are schematic diagrams of X-ray generators including aplurality of sensors according to an exemplary embodiment;

FIGS. 19A and 19B illustrate a panel on which sensors are locatedaccording to an exemplary embodiment;

FIG. 20 is a block diagram of an X-ray imaging apparatus according to anexemplary embodiment; and

FIG. 21 is a flowchart of an X-ray imaging method according to anexemplary embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout. In this regard,the exemplary embodiments may have different forms and should not beconstrued as being limited to the descriptions set forth herein. Also,the thickness or size of each element illustrated in the drawings may beexaggerated for convenience of explanation and clarity. Accordingly, theexemplary embodiments are merely described below, by referring to thefigures, to explain aspects of the present description.

The attached drawings for illustrating exemplary embodiments arereferred to in order to gain a sufficient understanding of the exemplaryembodiments, the merits thereof, and the objectives accomplished by theimplementation of the exemplary embodiments. The exemplary embodimentsmay, however, be embodied in many different forms and should not beconstrued as being limited to the exemplary embodiments set forthherein; rather, these exemplary embodiments are provided such that thisdisclosure will be thorough and complete, and will fully convey theconcept of the exemplary embodiments to one of ordinary skill in theart.

Hereinafter, the terms used in the specification will be brieflydescribed, and then the exemplary embodiments will be described indetail.

The terms used in this specification are those terms currently widelyused in the art in consideration of functions in regard to the exemplaryembodiment, but the terms may vary according to the intention of thoseof ordinary skill in the art, precedents, or new technology in the art.Also, specified terms may be selected by the applicant, and in thiscase, the detailed meaning thereof will be described in the detaileddescription of the exemplary embodiment. Thus, the terms used in thespecification should be understood not as simple names but based on themeaning of the terms and the overall description of the exemplaryembodiment.

In the present specification, an object may include a human being or ananimal, or a part of the human being or the animal. For example, theobject may include organs, such as the liver, the heart, the uterus, thebrain, breasts, the abdomen, or blood vessels. In the presentspecification, a “user” is a medical expert, for example, a doctor, anurse, a medical specialist, and a medical imaging expert, or anengineer managing medical apparatuses; however, the exemplaryembodiments are not limited thereto.

Expressions such as “at least one of,” when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list.

FIG. 1 is a schematic perspective view of an X-ray imaging apparatus 100according to an exemplary embodiment. The X-ray imaging apparatus 100 ofFIG. 1 is a mammography apparatus that images a breast but is notlimited thereto. The X-ray imaging apparatus 100 may apply to an X-rayimaging apparatus that contacts an object and generates an X-ray.

Referring to FIG. 1, the X-ray imaging apparatus 100 includes an X-raygenerator 10 that generates the X-ray, an X-ray detector 20 that detectsthe X-ray that is transmitted to an object 200, and panel 32 and thepanel 34 that may contact the object 200. The X-ray imaging apparatus100 may further include a gantry 40 that supports the X-ray generator10, the X-ray detector 20, and the panel 32 and the panel 34, and a mainbody 50 that supports the gantry 40.

The main body 50 may include a user input device 52 in which a user mayinput a command to operate the X-ray imaging apparatus 100, a processor(not shown) that generates an image corresponding to the transmittedX-ray, a display 54 that displays the generated image, and a controller(not shown) that controls general operations of the X-ray imagingapparatus 100. The user input device 52, the processor (not shown), thedisplay 54, and the controller (not shown) may not be necessarilyincluded in the main body 50, and may be implemented as external devicesthat may communicate with the X-ray imaging apparatus 100 by wire orwireless sly.

The gantry 40 may be fixed to the main body 50 via a gantry driver 42.The gantry 40 may be located on one side surface of the main body 50longitudinally. The gantry driver 42 may rotate the gantry 40 by 360° orat an angle. In addition, the gantry driver 42 may operate to move thegantry 40 up and down longitudinally with respect to the main body 50.Thus, the gantry driver 42 may move the gantry 40 up or downlongitudinally with respect to the main body 50 so that a height of thegantry 40 may be adjusted in accordance with the object 200, and mayrotate the gantry 40.

The panel 32 and the panel 34 may contact the object 200, for example,the first panel 32 and the second panel 34, may be located on the frontof the gantry 40. The first panel 32 and the second panel 34 may move upand down by using a guide groove 44 that is longitudinally included onthe front of the gantry 40. Thus, if the object 200, for example,breasts of a patient, is placed between the first panel 32 and thesecond panel 34, at least one of the first panel 32 and the second panel34 may press the object 200 to compress the object 200. For example, thesecond panel 34 may move up or down to allow the object 200 to bepositioned on the second panel 34 and then the first panel 32 may movedown to press the object 200 and compress the object 200.

The X-ray generator 10 that generates the X-ray may be located on thefirst panel 32. The X-ray generator 10 may be moved away from or closerto the object 200 while maintaining a distance d with the first panel32. For example, the X-ray generator 10 may be integrated with the firstpanel 32 so that the X-ray generator 10 and the first panel 32 may movealong the guide groove 44.

In more detail, when the first panel 32 presses the object 200, sincethe X-ray generator 10 radiates the X-ray toward the object 200, adistance between the X-ray generator 10 and the object 200 may beminimized. For example, the distance between the X-ray generator 10 andthe object 200 may be about 10 cm. Thus, the emission of X-ray radiationto a region other than the object 200 may be prevented, therebyminimizing the amount of X-ray radiation which is emitted. To minimizethe distance between the X-ray generator 10 and the object 200, theX-ray generator 10 may be located so as to contact a side of the object200, such as the top side of a human breast. The X-ray generator 10includes a plurality of X-ray sub-generators 300, which will bedescribed later.

The X-ray detector 20 that detects the X-ray that is transmitted to theobject 200 may be provided under the second panel 34. The X-ray detector20 may be moved away from or closer to the object 200 while maintaininga distance d with the second panel 34. For example, the X-ray detector20 may be integrated with the second panel 34 so that the X-ray detector20 and the second panel 34 move along the guide groove 44.

In more detail, when the object 200 is positioned on the second panel34, since the X-ray detector 20 detects the X-ray that is transmitted tothe object 200, a distance between the X-ray detector 20 and the object200 may be minimized. Thus, the X-ray may be more exactly detected. Tominimize the distance between the X-ray detector 20 and the object 200,the X-ray detector 20 may be disposed to contact a side of the object200 such as a bottom side of a human breast. The X-ray detector 20includes a plurality of X-ray detectors, which will be described later.

The X-ray generator 10 will now be described in more detail below. FIGS.2A and 2B are schematic diagrams of X-ray generators 10 a and 10 bincluding the plurality of X-ray sub-generators 300 according to anexemplary embodiment. Referring to FIG. 2A, the X-ray generator 10 a mayinclude X-ray sub-generators 300 arranged in one dimension. Referring toFIG. 2B, the X-ray generator 10 b may include the X-ray sub-generators300 arranged in two dimensions.

Each of the X-ray sub-generators 300 may be independently driven togenerate an X-ray. Accordingly, all of the X-ray sub-generators 300 maybe driven to radiate X-rays toward the object 200 or only some of theX-ray sub-generators 300 may be driven to radiate X-rays to the object200. At least one of the X-ray sub-generators 300 may radiate X-rays toall regions of the object 200 or to only a specific region. In addition,at least one of the X-ray sub-generators 300 may be simultaneously orsequentially driven. In this case, only some X-ray sub-detectorscorresponding to the X-ray sub-generators 300 that are being driven maybe driven.

Although the X-ray sub-generators 300 are respectively formed on asingle substrate, such as substrate 11 and substrate 12 in FIGS. 2A and2B, the exemplary embodiment is not limited thereto. Each of the X-raysub-generators 300 may be separately manufactured and the X-raysub-generators 300 may be assembled into the X-ray generators 10 a and10 b. Alternatively, some of the X-ray sub-generators 300 may be formedon a single substrate and then assembled together with other X-raysub-generators 300 formed on other substrates. For example, an X-raygenerator which is two dimensional may be manufactured by generatingX-ray generators in one dimension on a single substrate and arrangingthe X-ray generators in one dimension. Although not shown, an X-raycontroller can be provided to control a proceeding path of an X-raygenerated by each of the X-ray sub-generators 300 so as to not interferewith a neighboring X-ray. In the X-ray controller, an opening is formedin an area corresponding to each of the X-ray sub-generators 300 and anX-ray absorbing material may be formed in a grid type in the other area(for example, a boundary area between the neighboring X-raysub-generators 300).

FIGS. 3A to 3D are schematic diagrams of X-ray sub-generators 300 a, 300b, 300 c, and 300 d according to exemplary embodiments. Referring toFIG. 3A, the X-ray sub-generator 300 a may include an electron emissiondevice 310 a that may emit electrons and an anode electrode 320 a thatmay emit an X-ray by collision of the emitted electrons. The anodeelectrode 320 a may include metal or a metal alloy such as tungsten (W),molybdenum (Mo), silver (Ag), chromium (Cr), iron (Fe), cobalt (Co),copper (Cu), etc.

The electron emission device 310 a may include a cathode electrode 312and an electron emission source 314 arranged on the cathode electrode312 that emits electrons. The cathode electrode 312 may be metal such astitanium (Ti), platinum (Pt), ruthenium (Ru), gold (Au), Ag, Mo,aluminum (Al), W, or Cu, or a metal oxide such as indium tin oxide(ITO), aluminum zinc oxide (AZO), indium zinc oxide (IZO), tin oxide(SnO₂), or indium oxide (In₂O₃). The electron emission source 314 may beformed of a material capable of emitting electrons. For example, theelectron emission source 314 may be formed of metal, silicon, an oxide,diamond, diamond like carbon (DLC), a carbide compound, a nitrogencompound, carbon nanotube, carbon nanofiber, etc.

The cathode electrode 312 applies a voltage to the electron emissionsource 314. When a voltage difference occurs between the electronemission source 314 and the anode electrode 320 a, that is, the cathodeelectrode 312 and the anode electrode 320 a, the electron emissionsource 314 emits electrons and the electrons collide with the anodeelectrode 320 a. Accordingly, the anode electrode 320 a radiates anX-ray due to the collision of electrons.

As shown in FIG. 3B, an electron emission device 310 b of the X-raysub-generator 300 b may further include a gate electrode 316 between theelectron emission source 314 and the anode electrode 320 a. The gateelectrode 316 may be formed of the same material as the cathodeelectrode 312. The electron emission source 314 may emit electrons bythe voltage difference between the gate electrode 316 and the cathodeelectrode 312. As the gate electrode 316 is arranged between the cathodeelectrode 312 and the anode electrode 320 a, the electrons induced bythe electron emission source 314 by the voltage applied to the gateelectrode 316 may be controlled. Accordingly, the X-ray sub-generator300 b may more stably control the emission of electrons.

In addition, as shown in FIG. 3C, an electron emission device 310 c ofthe X-ray sub-generator 300 c may further include a focusing electrode318 between the electron emission source 314 and an anode electrode 320b. The focusing electrode 318 may be formed of the same material as thecathode electrode 312. The focusing electrode 318 focuses the electronsemitted from the electron emission source 314 on an area of the anodeelectrode 320 b so as to collide therewith. A voltage applied to thefocusing electrode 318 may be the same as or similar to the voltageapplied to the gate electrode 316 so that an optimal focusingperformance may be maintained.

As shown in FIG. 3D, an electron emission device 310 d of the X-raysub-generator 300 d may include the cathode electrode 312, the electronemission source 314 arranged on the cathode electrode 312 that emitselectrons, the gate electrode 316 spaced apart from the cathodeelectrode 312, and the focusing electrode 318 focusing the emittedelectrons.

FIG. 4 illustrates an electron emission device 400 including a gateelectrode 420, according to an exemplary embodiment.

Referring to FIG. 4, the electron emission device 400 may include acathode electrode 410, the gate electrode 420 having a mesh structurespaced apart from the cathode electrode 410, a plurality of insulationlayers 430 and a plurality of electron emission sources 440 that extendin a first direction between the cathode electrode 410 and the gateelectrode 420 and are spaced apart from each other. A substrate 450 forsupporting the electron emission device 400 may be formed of aninsulation material such as glass. The substrate 450 may support asingle electron emission device 400 or the electron emission devices440.

The cathode electrode 410 and the gate electrode 420 may be formed of aconductive material. The cathode electrode 410 may apply a voltage toeach of the electron emission sources 440 and may have a flat panelshape. When the cathode electrode 410 has a flat panel shape, thesubstrate 450 may not be necessary. The gate electrode 420 may have amesh structure including a plurality of openings H. For example, thegate electrode 420 may include a plurality of gate lines 422 separatedfrom each other and arranged on the insulation layers 430 and aplurality of gate bridges 424 connecting the gate lines 422.Accordingly, the two neighboring gate lines 422 and the two neighboringgate bridges 424 form the openings H.

The openings H may be arranged to expose at least a part of the electronemission sources 440 between the insulation layers 430. As describedabove, since the gate electrode 420 has a mesh structure, a largeelectron emission device 400 may be manufactured. Although the openingsH of the gate electrode 420 are each rectangular in FIG. 4, theexemplary embodiment is not limited thereto. The shape of the openings Hcan also be, for example, circles, ovals, and polygons. The sizes of theopenings H of the electron emission device 400 may be identical ordifferent.

The insulation layers 430 are arranged between the cathode electrode 410and the gate electrode 420 and prevent an electrical connection betweenthe cathode electrode 410 and the gate electrode 420. The insulationlayers 430 are arranged in multiple numbers and at least threeinsulation layers 430 may be provided. The insulation layers 430 mayhave a linear shape. The insulation layers 430 extend in one directionand are separate from one another and support the gate electrode 420.The insulation layers 430 may each include a first insulation layer 432supporting an edge area of the gate electrode 420 and a secondinsulation layer 434 supporting a middle area of the gate electrode 420.

The insulation layers 430 may be formed of an insulation material usedfor a semiconductor device. For example, the insulation layers 430 maybe formed of hafnium(IV) oxide (HfO₂), aluminum oxide (Al₂O₃), orsilicon nitride (Si₃N₄), which is a high-K material having a higherdielectric rate than SiO₂.

Although the insulation layers 430 have a linear shape in FIG. 4, thepresent exemplary embodiment is not limited thereto. The insulationlayers 430 may have a different shape that prevents an electricalconnection between the cathode electrode 410 and the gate electrode 420and supports the gate electrode 420. For example, the second insulationlayer 434 may have a column shape and may be arranged under the gatelines 422.

The electron emission sources 440 emit electrons due to the voltageapplied to the cathode electrode 410 and the gate electrode 420. Theelectron emission device 400 of FIG. 4 may include the electron emissionsources 440. The electron emission sources 440 may be alternatelyarranged with the insulation layers 430. For example, the electronemission sources 440 may be spaced apart from one another with thesecond insulation layer 434 interposed between the neighboring electronemission sources 440. The electron emission sources 440 may have formedof strips extending in the first direction, which is a direction similarto the second insulation layer 434.

Since the gate electrode 420 has a mesh structure, the gate electrode420 is arranged above the electron emission sources 440. The electronemission sources 440 may be spaced apart from the gate electrode 420 toprevent the electron emission sources 440 and the gate electrode 420from being short-circuited.

The electron emission sources 440 may be formed of a material capable ofemitting electrons. As an area occupied by the electron emission sources440 in the electron emission device 400 increases, the electron emissiondevice 400 may emit a large amount of electrons. However, the electronemission device 400 may endure an electrostatic force due to adifference in the voltages applied between the electron emission sources440 and the gate electrode 420. Accordingly, the insulation layers 430and the electron emission sources 440 are alternately arranged, and thegate electrode 420 having the opening H is arranged over an area whereeach of the electron emission sources 440 is arranged, therebyimplementing the large area electron emission device 400.

Since the gate electrode 420 includes the gate bridges 424 arranged in adirection crossing the lengthwise direction of the electron emissionsources 440, a uniform electric field may be formed on surfaces of theelectron emission sources 440.

Although the electron emission sources 440 are formed in strips in FIG.4, the present exemplary embodiment is not limited thereto. The electronemission sources 440 may be formed as a point type in an areacorresponding to the opening H above the cathode electrode 410. Thepoint-type electron emission sources 440 may be arranged in a twodimensional array, that is, in a matrix format.

Although the electron emission sources 440 are arranged in the singleelectron emission device 400 in FIG. 4, the present exemplary embodimentis not limited thereto. Also, only one electron emission source may bearranged in the electron emission device 400 or two or more electronemission sources may be arranged in the electron emission device 400.

A path of the X-ray may be controlled by the shape of an anodeelectrode. In detail, if the thickness of the anode electrode isprovided to be of an irregular thickness, the path at which the X-rayradiated from the anode electrode proceeds may be controlled.

FIGS. 5A to 5G illustrate anode electrodes having irregular thicknessesaccording to exemplary embodiments. The anode electrode illustrated ineach of FIGS. 5A to 5G corresponds to a single X-ray generator. However,the present exemplary embodiment is not limited thereto. One anodeelectrode may correspond to one electron emission device. Forconvenience of explanation, one anode electrode corresponding to thesingle X-ray generator will be described below.

As shown in FIGS. 5A to 5G, the anode electrode may be symmetricallyprovided about a center axis Z of the X-ray generator 10 so that anX-ray may be symmetrically radiated.

The thicknesses of anode electrodes 510 and 520 gradually decrease fromthe center axis Z of the X-ray generator 10 toward edges thereof, asillustrated in FIGS. 5A and 5B. When the thicknesses of the anodeelectrodes 510 and 520 gradually decrease from the center axis Z of theX-ray generator 10 toward edges thereof, X-rays radiated from the anodeelectrodes 510 and 520 may propagate so as to be focused at the centeraxis Z of the X-ray generator 10. Thus, the X-ray generator 10 mayefficiently radiate an X-ray toward a part of the object.

In more detail, surfaces 512 and 522 of the anode electrodes 510 and520, on which electrons are incident, may be flat surfaces, whereassurfaces 514 and 524 from which X-rays are emitted may be convexsurfaces. The surfaces 514 and 524 from which X-rays are emitted may beconvexly curved surfaces or convex surfaces obtained by combining flatsurfaces. A position where the X-ray is focused may be determined bylevels, θ and R, of the convex shape. Although in FIGS. 5A and 5B thesurfaces 512 and 522 of the anode electrodes 510 and 520, respectively,on which electrons are incident are flat and the surfaces 514 and 524from which X-rays are emitted are convex, the present exemplaryembodiment is not limited thereto. That is, the surfaces on whichelectrons are incident may be convex, whereas the surfaces from whichX-rays are emitted may be flat.

The thicknesses of anode electrodes 530 and 540 gradually increase fromthe center axis Z of the X-ray generator 10 toward edges thereof, asillustrated in FIGS. 5C and 5D. When the thicknesses of the anodeelectrodes 530 and 540 increase from the center axis Z of the X-raygenerator 10 toward edges thereof, the X-ray radiated from each of theanode electrodes 530 and 540 may propagate toward an area larger than asectional area of each of the anode electrodes 530 and 540. Thus, theX-ray generator 10 may radiate an X-ray to a relatively large area of anobject.

In more detail, surfaces 532 and 542 of the anode electrode 530 and 540,respectively, on which electrons are incident, may be flat surfaces,whereas surfaces 534 and 544 from which X-rays are emitted may beconcave surfaces. The surfaces 534 and 544 from which X-rays are emittedmay be concavely curved surfaces or concave surfaces obtained bycombining flat surfaces. A size of an area where the X-ray is radiatedmay be determined by levels, θ and R, of the concave shape. Although inFIGS. 5C and 5D the surfaces 532 and 542 of the anode electrodes 530 and540 on which electrons are incident are flat and the surfaces 534 and544 from which X-rays are emitted are concave, the present exemplaryembodiment is not limited thereto. That is, the surfaces on whichelectrons are incident may be concave, whereas the surfaces from whichX-rays are emitted may be flat.

In addition, as shown in FIG. 5E, both surfaces of an anode electrode550 on which electrons are incident and from which X-rays are emittedmay be convex. In this case, a focal distance of an X-ray may becomeshorter. Additionally, both surfaces on which electrons are incident andfrom which X-rays are emitted may be concave. Alternatively, while oneof the surfaces on which electrons are incident and from which X-raysare emitted may be concave, the other surface may be convex.

The thickness of an anode electrode may be partially irregular. Forexample, as it is illustrated in FIGS. 5F and 5G, anode electrodes 560and 570 may have a shape in which only some parts are convex. A convexshape 566 may be identical to other convex shapes, as shown on the anodeelectrode 560, or a convex shape 576 may be different from other convexshapes, as shown on the anode electrode 570, according to an area.Nevertheless, the thicknesses of the anode electrodes 560 and 570 may besymmetrical with respect to the center axis Z of the X-ray generator 10.Although FIGS. 5F and 5G illustrate only a convex shape, the presentexemplary embodiment is not limited thereto. The anode electrode mayhave a concave shape or both a concave shape and a convex shape.Surfaces 562 and 572 of the anode electrodes 560 and 570, respectively,on which electrons are incident, may be flat surfaces.

As such, since the propagating path of an X-ray may be controlled byusing the anode electrode having an irregular thickness, the X-raygenerator 10 may not only efficiently radiate an X-ray toward theobject, but may also decrease the amount of radiation emitted, therebyreducing an amount of an X-ray radiation dose.

The X-ray imaging apparatus 100 according to the present exemplaryembodiment may use an anode electrode having a uniform thickness. FIG. 6illustrates an anode electrode 580 having a uniform thickness, accordingto an exemplary embodiment. Referring to FIG. 6, while the anodeelectrode 580 having a uniform thickness is used, the propagating pathof an X-ray may be controlled by using a separate constituent elementsuch as a collimator (not shown).

In addition, the anode electrode may include a plurality of layersformed of different materials and are capable of radiating X-rays ofdifferent wavelengths. FIG. 7 illustrates an anode electrode 710 formedof different materials, according to an exemplary embodiment. As shownin FIG. 7, the anode electrode 710 may include a plurality of layers711, 712, 713, and 714 formed of different materials. The layers 711,712, 713, and 714 may be arranged in parallel with respect to anelectron emission device. The anode electrode 710 may radiate X-rays ofdifferent wavelengths according to the layers 711, 712, 713, and 714with which electrons collide.

An anode electrode radiating X-rays of multiple wavelengths may notnecessarily have a uniform thickness as described above. FIGS. 8A and 8Billustrate anode electrodes 810 and 820 formed of different materials,according to exemplary embodiments. Each of the anode electrodes 810 and820 may include a plurality of layers formed of different materials andat least one of the layers may have an irregular thickness.

For example, as shown in FIG. 8A, the anode electrode 810 may include aplurality of layers 811, 812, 813, and 814 that are formed of differentmaterials. The layers 811, 812, 813, and 814 have thicknesses thatgradually decrease from the center axis Z of the X-ray generator 10toward edges thereof. Accordingly, the anode electrode 810 may focus theradiated X-rays. Since the X-rays having different wavelengths arefocused on different areas, a single linear X-ray generator may imagemany different areas at different depths of the object at one time.

In addition, as shown in FIG. 8B, the anode electrode 820 may include aplurality of layers 821, 822, and 823 that are formed of differentmaterials. The anode electrode 820 may have a change in the thicknessthereof according to the layers 821, 822, and 823. For example, thefirst layer 821 may have a thickness that gradually decreases from thecenter axis Z of the X-ray generator 10 toward an edge thereof, thesecond layer 822 may have a uniform thickness, and the third layer 823may have a thickness that gradually increases from the center axis Z ofthe X-ray generator 10 toward the edge thereof. Accordingly, the anodeelectrode 820 may radiate an X-ray to a larger surrounding area whilefocusing on an area of interest of the object.

The X-ray generator 10 according to the present exemplary embodiment maysimultaneously or selectively generate X-rays of different wavelengths.FIGS. 9A to 9C illustrate an X-ray generator generating an X-ray of ashort wavelength or simultaneously generating X-rays of a plurality ofwavelength bands, according to exemplary embodiments.

Referring to FIG. 9A, a plurality of electron emission devices 910, eachhaving an electron emission source 912, are arranged and an anodeelectrode 920 may be arranged separately from the electron emissiondevices 910. In the anode electrode 920, a first layer 922 and a secondlayer 924 that are formed of different materials may be alternatelyarranged. When the first layer 922 and the second layer 924 overlap witheach other in an area corresponding to the electron emission source 912of one of the electron emission devices 910, electrons emitted by theelectron emission devices 910 may collide with the first layer 922 andsecond layer 924. Accordingly, the anode electrode 920 maysimultaneously radiate a first X-ray X1 and a second X-ray X2.

As shown in FIG. 9B, the anode electrode 920 makes a translationalmovement in parallel with the electron emission devices 910 such thatthe first layer 922 of the anode electrode 920 may be arranged tooverlap with the electron emission source 912. Then, the electronsemitted by the electron emission devices 910 collide with the firstlayer 922 and thus the first X-ray X1 may be radiated from the anodeelectrode 920.

As shown in FIG. 9C, the anode electrode 920 makes a translationalmovement in parallel with the electron emission devices 910 such thatthe second layer 924 of the anode electrode 920 may be arranged tooverlap with the electron emission source 912. Then, the electronsemitted by the electron emission devices 910 collide with the secondlayer 924 and thus the second X-ray X2 may be radiated from the anodeelectrode 920.

As such, since the anode electrode 920 simultaneously radiates aplurality of X-rays or selectively radiates a single X-ray, usability ofthe X-ray generator 10 may be improved.

As described above, X-ray sub-generators are arranged in an X-raygenerator 10. Each of the X-ray sub-generators is separatelymanufactured as one unit and then the X-ray sub-generators areassembled, thereby forming the X-ray generator. A plurality of electronemission devices and an anode electrode may be integrally manufacturedon a single substrate. Alternatively, a plurality of electron emissiondevices are manufactured on a single substrate and then an anodeelectrode is assembled, thereby forming a linear X-ray generator. Inaddition, the linear X-ray generator may be formed by a variety ofmethods.

Additionally, the X-ray generator may further include a collimator (notshown) for controlling a direction of an X-ray. Accordingly, the amountof X-ray radiation which is emitted may be reduced, and an X-ray may bealso more accurately detected.

FIGS. 10A and 10B schematically illustrate X-ray detector 1000 a andX-ray detector 1000 b that may be used as the X-ray detector 20 ofFIG. 1. As shown in FIG. 10A, the X-ray detector 1000 a may beconfigured as a plurality of X-ray sub-detectors 1010 arranged in onedimension. Alternatively, as shown in FIG. 10B, the X-ray detector 1000b may be configured as the plurality of X-ray sub-detectors 1010arranged in two dimensions.

Each of the X-ray sub-detectors 1010 is a light-receiving element thatreceives an X-ray and converts a received X-ray into an electric signal,and may include, for example, a scintillator 1011, a photodiode 1012,and a storage element 1013. The scintillator 1011 receives an X-ray andoutputs photons, in particular visible photons, that is, a visible ray,according to a received X-ray. The photodiode 1012 receives the photonsoutput from the scintillator 1011 and converts received photons intoelectric signals. The storage element 1013 is electrically connected tothe photodiode 1012 and stores the electric signal output from thephotodiode 1012. In this regard, the storage element 1013 may be, forexample, a storage capacitor. The electric signal stored in the storageelement 1013 of each of the X-ray sub-detectors 1010 is applied to aprocessor (not shown) where the signal is processed into an X-ray image.

The X-ray detectors 1000 a and 1000 b may detect an X-ray by using aphotoconductor which directly converts an X-ray into an electric signal.

The X-ray sub-detectors 1010 may be provided to correspond to the X-raysub-generators 300 of an X-ray generator. The X-ray sub-generators 300and the X-ray sub-detectors 1010 may have a one-to-one correspondence.Alternatively, each of the X-ray sub-generators 300 may correspond totwo or more X-ray sub-detectors 1010, or two or more X-raysub-generators 300 may correspond to one X-ray sub-detector 1010.

The X-ray sub-detectors 1010 may be simultaneously or independentlydriven to detect an X-ray. Accordingly, an X-ray passing through theentire area of the object may be detected as all of the X-raysub-detectors 1010 are driven, or an X-ray passing through a particulararea of the object may be detected as some of the X-ray sub-detectors1010 are driven. Also, at least one of the X-ray sub-detectors 1010 maybe simultaneously or sequentially driven.

Although the X-ray sub-detectors 1010 are formed on a single substrate,the present exemplary embodiment is not limited thereto. Each of theX-ray sub-detectors 1010 is separately manufactured, and the X-raysub-detectors 1010 are assembled into the X-ray detectors 1000 a and1000 b. Alternatively, some of the X-ray sub-detectors 1010 are formedon a single substrate and then assembled together with the other X-raysub-detectors 1010 formed on other substrates. For example, X-raydetectors in one dimension are generated on a single substrate and arethen arranged, and thus X-ray detectors in two dimensions may bemanufactured.

When an X-ray generation area of the X-ray generator and X-ray detectionareas of the X-ray detectors 1000 a and 1000 b are equal to or largerthan a test area of the object, the linear X-ray generator and the X-raydetectors 1000 a and 1000 b may image the object by performing a singleoperation. The X-ray imaging apparatus 100 may image the whole object atone time or a partial area of the object. When a partial area of theobject is to be imaged, only some of the X-ray sub-generators 300 of theX-ray generator may operate to generate an X-ray, and only some of theX-ray sub-detectors 1010 corresponding to the operating X-raysub-generators 300 may be synchronized to detect the X-ray.

However, when at least one of the X-ray generation area of the X-raygenerator and the X-ray detection areas of the X-ray detectors 1000 aand 1000 b is smaller than the test area of the object, at least one ofthe X-ray generator and the X-ray detectors 1000 a and 1000 b may moveto be driven two times or more.

FIGS. 11A and 11B are diagrams for explaining an X-ray imaging methodwhen an X-ray generation area A is smaller than a test area B of theobject 200 according to an exemplary embodiment. When the X-raygeneration area A of an X-ray generator 1110 is smaller than the testarea B, the X-ray generator 1110 may move along a first panel 1132 togenerate an X-ray, thereby generating the X-ray in the entire test areaB of the object 200.

For example, referring to FIG. 11A, the X-ray generator 1110 radiates anX-ray to a first area B1 of the object 200. Then, a first detector 1122of an X-ray detector 1120 next to a second panel 1134 detects an X-raythat was transmitted to the first area B1. Referring to FIG. 11B, theX-ray generator 1110 horizontally moves along the first panel 1132 andthen radiates an X-ray to a second area B2 of the object 200. In thisregard, the second area B2 and the first area B1 may not overlap witheach other. Thus, an X-ray radiation dose of the object 200 may beminimized. A second detector 1124 of the X-ray detector 1120corresponding to the first area B1 detects an X-ray of the second areaB2. Although the X-ray generation area A of the X-ray generator 1110 ishalf of the test area B in FIGS. 11A and 11B, the present exemplaryembodiment is not limited thereto. The X-ray generation area A may be1/n (where n is a natural number equal to or greater than 2) the testarea B.

FIGS. 12A and 12B are diagrams for explaining an X-ray imaging methodwhen an X-ray detection area C is smaller than the test area B of anobject according to an exemplary embodiment. When the X-ray detectionarea C of the X-ray detector 1220 is smaller than the test area B, theX-ray detector 1220 may move along a second panel 1234 to detect anX-ray, thereby detecting the X-ray that is transmitted to the entiretest area B of the object 200.

For example, referring to FIG. 12A, a first X-ray generator 1212 of anX-ray generator 1210 next to first panel 1232 generates X-rays to betransmitted to the first area B1 of the object 200. Then, an X-raydetector 1220 detects an X-ray of the first area B1. Referring to FIG.12B, the X-ray detector 1220 horizontally moves along the second panel1234. Then, a second X-ray generator 1214 of the X-ray generator 1210emits X-rays to be transmitted to the second area B2 of the object 200.The X-ray detector 1220 detects an X-ray of the second area B2. In thisregard, the second area B2 and the first area B1 may not be overlappingwith each other. Thus, an amount of X-ray radiation transmitted to theobject 200 may be minimized. Although the X-ray detection area C of theX-ray detector 1120 is half of the test area B in FIGS. 12A and 12B, thepresent exemplary embodiment is not limited thereto. The X-ray detectionarea C may be 1/n (where n is a natural number equal to or greater than2) the test area B.

In addition, when the X-ray generation area A and the X-ray detectionarea C are smaller than the test area B and correspond to each otherone-to-one, the X-ray generators 1110 and 1210 and the X-ray detectors1120 and 1220 may be synchronized to image a part of a region of thetest area B. The X-ray generator 1110 may horizontally move along firstpanel 1132 and the X-ray detector 1120 may move along second panel 1134in order to image other areas of the test area B. Also, the X-raygenerator 1210 may horizontally move along first panel 1232 and theX-ray detector 1220 may move along the second panel 1234 in order toimage other areas of the test area B.

When the X-ray generation area A and the X-ray detection area C aresmaller than the test area B, and the X-ray generation area A is smallerthan the X-ray detection area C, the X-ray imaging method of FIGS. 12Aand 12B may be applied to image a partial region of the test area B.Each of the X-ray generators 1110 and 1210 and the X-ray detectors 1120and 1220 may horizontally move along the first and second panels 1132and 1134 and the first and second panels 1232 and 1234, respectively,and image other regions of the test area B. Furthermore, when the X-raygeneration area A and the X-ray detection area C are smaller than thetest area B, and the X-ray detection area C is smaller than the X-raygeneration area A, the X-ray imaging method of FIGS. 12A and 12B may beapplied to image a partial region of the test area B.

Meanwhile, the X-ray imaging apparatus 100 according to an exemplaryembodiment may acquire a tomography image of the object 200. To acquirethe tomography image, the X-ray generators may radiate an X-ray towardthe object by varying a radiation angle of the X-ray toward the object.The X-ray generators according to an exemplary embodiment may vary theradiation angle to the object by moving horizontally with respect to theobject. In this regard, horizontal movement means horizontal movement ofthe center axes of the X-ray generators.

To acquire the tomography image, the X-ray generators may radiate anX-ray to the object at multiple locations. When the X-ray is radiated atmultiple locations, the center axes of the X-ray generators may move inparallel with the object. Furthermore, the X-ray generators may radiatean X-ray by varying a radiation angle according to locations of theX-ray generators. For example, the X-ray generators may radiate an X-rayto the object vertically at a first location and then radiate an X-rayat an incline at a second location. In this regard, the X-ray detectorsmay be located under the object. The X-ray detectors may be in a fixedposition.

FIGS. 13A through 13C are diagrams for explaining an X-ray imagingmethod so as to acquire a tomography image according to an exemplaryembodiment. Referring to FIG. 13A, when an X-ray generator 1310 islocated on a left upper portion of the object 200, the X-ray generator1310 may rotate with respect to a center axis P1 thereof such that anX-ray radiation direction is changed from the left upper portion to aright lower portion. The X-ray generator 1310 located above the panel1332 radiates an X-ray at a first radiation angle θ1 toward the object200, and thus an X-ray imaging apparatus may image a first image of theobject 200.

The X-ray generator 1310 can be moved to the right. When the X-raygenerator 1310 moves, the center axis P1 of the X-ray generator 1310 maymove in parallel with the object 200. When the X-ray generator 1310 islocated on the object 200, the X-ray generator 1310 may adjust itsposture to allow an X-ray to face the object 200. For example, the X-raygenerator 1310 may rotate in a clockwise direction with respect to thecenter axis P1 of the X-ray generator 1310. As shown in FIG. 13B, theX-ray generator 1310 may be located in parallel with the object 200. TheX-ray generator 1310 may vertically radiate an X-ray to the object 200.The X-ray imaging apparatus may also image a second image of the object200. As shown in FIGS. 13A and 13B, an X-ray detector 1320 located nextto panel 1334 detects the X-rays.

The X-ray generator 1310 may move in parallel with the object 200, forexample, towards the right side of the object, until the X-ray generator1310 is located on a right upper portion of the object 200. When theX-ray generator 1310 is located on the right upper portion of the object200, the X-ray generator 1310 may adjust its posture to allow an X-raygenerated by the X-ray generator 1310 to be radiated at an incline tothe object 200. For example, as shown in FIG. 13C, the X-ray generator1310 may rotate in a clockwise direction with respect to the center axisP1 of the X-ray generator 1310. The X-ray generator 1310 may radiate anX-ray at a second radiation angle θ2 toward the object 200, and thus theX-ray imaging apparatus may image a third image of the object 200.

When the X-ray generator 1310 moves in a horizontal direction withrespect to an X-ray detector 1320, the X-ray generator 1310 rotates withrespect to the center axis P1 thereof according to a location. The orderof movement, such as an order of horizontal movement and rotationalmovement, may be switched. Also, the second image of the object 200 maybe imaged in advance and a first image or a third image may be obtained.

The X-ray detector 1320 may detect an X-ray by moving so as tocorrespond to the X-ray generator 1310. FIGS. 14A through 14C arediagrams for explaining an X-ray imaging method so as to acquire atomography image according to another exemplary embodiment.

Referring to FIG. 14A, when the X-ray generator 1310 is located on aleft upper portion of the object 200, the X-ray generator 1310 mayrotate with respect to the center axis P1 thereof such that an X-ray maybe radiated at an incline to the object 200. In this regard, the X-raydetector 1320 may also move to face the X-ray generator 1310. Forexample, the X-ray detector 1320 may move to be located on a right lowerportion of the object 200 and rotate with respect to a center axis P2 ofthe X-ray detector 1320 such that the X-ray generator 1310 and the X-raydetector 1320 may be located in parallel with each other. The X-raygenerator 1310 may radiate an X-ray at a first radiation angle θ3 to theobject 200. Thus, an X-ray imaging apparatus may obtain a first image ofthe object 200.

Referring to FIG. 14B, the X-ray generator 1310 may move so as to belocated on the object 200. Furthermore, the X-ray generator 1310 mayadjust its posture such that the X-ray generator 1310 may be located inparallel with the object 200. In this regard, the X-ray detector 1320may also move. For example, the X-ray detector 1320 may move to belocated under the object 200 and rotate with respect to the center axisP2 thereof such that the X-ray generator 1310, the object 200, and theX-ray detector 1320 may be located in parallel with each other. TheX-ray generator 1310 may vertically radiate an X-ray toward the object200, and thus the X-ray imaging apparatus may acquire a second image ofthe object 200.

Referring to FIG. 14C, the X-ray generator 1310 may move toward a rightupper portion of the object 200 and adjust its posture such that anX-ray is radiated at an incline toward the object 200. In this regard,the X-ray detector 1320 may also move to be located in parallel to theX-ray generator 1310. For example, the X-ray detector 1320 may move tobe located on a left lower portion of the object 200 and rotate withrespect to the center axis P2 thereof such that the X-ray generator1310, the object, 200, and the X-ray detector 1320 may be located inparallel to each other. The X-ray generator 1310 may radiate an X-ray ata second radiation angle θ4 to the object 200, and thus the X-rayimaging apparatus may acquire a third image of the object 200.

As described above, the X-ray generator 1310 may move to vary aradiation angle of an X-ray and radiate the X-ray to the object 200,thereby simplifying an imaging process for acquiring a tomography image.

Furthermore, in the exemplary embodiment, the X-ray generator 1310 andthe X-ray detector 1320 can be fixed or the X-ray generator 1310 and theX-ray detector 1320 can rotate to acquire the tomography image.

FIG. 15 is a schematic diagram of an X-ray generator 1510 according toan exemplary embodiment. Referring to FIG. 15, the X-ray generator 1510according to an exemplary embodiment may include a plurality of X-raysub-generators 1511 arranged in one dimension and a rotator 1513 thatsupports and rotates the X-ray sub-generators 1511. The X-ray generator1510 may include a driver (not shown) that drives the rotator 1513. Ifthe rotator 1513 rotates at a predetermined time interval, the X-raysub-generators 1511 located on the rotator 1513 may radiate an X-ray toan object at different radiation angles at the predetermined timeinterval. An X-ray detector may include a rotator like the X-raygenerator 1510.

FIGS. 16A through 16C are diagrams for explaining an X-ray imagingmethod so as to acquire a tomography image according to anotherexemplary embodiment.

Referring to FIG. 16A, a rotator 1613 may rotate such that each X-raysub-generator 1611 of an X-ray generator 1610 may radiate an X-ray tothe object 200 at the first radiation angle θ3 at a first time. Forexample, the rotator 1613 may rotate in a counterclockwise directionwhen imagining is being performed a first time. The X-ray generator 1610may radiate the X-ray to the object 200 at the first radiation angle θ3,and thus an X-ray imaging apparatus may acquire a first image of theobject 200. FIGS. 16A, 16B and 16C also illustrates a first panel 1632,a second panel 1634 and an X-ray detector 1620.

Referring to FIG. 16B, each X-ray sub-generator 1611 rotates in acounterclockwise direction at a second time after a predetermined timeelapses and then the X-ray generator 1610 may vertically radiate anX-ray to the object 200. The X-ray imaging apparatus may acquire asecond image of the object 200. Furthermore, referring to FIG. 16C, eachof the X-ray sub-generators 1611 rotates in a clockwise direction at athird time after a predetermined time elapses and then the X-raygenerator 1610 may vertically radiate an X-ray to the object 200 at thesecond radiation angle θ4. The X-ray imaging apparatus may then acquirea third image of the object 200. In this regard, X-ray sub-detectors1621 may rotate like the X-ray sub-generators 1611 to detect an X-ray.

As described above, an X-ray radiation angle may be changed by rotatingonly the X-ray sub-generators 1611, thereby simplifying an imagingprocess for acquiring the tomography image.

Furthermore, a shape of an anode electrode among the X-raysub-generators 1611 may be used to change the X-ray radiation angle withrespect to the object 200. FIG. 17 is a schematic diagram of an X-raygenerator 1710 used to acquire a tomography image according to anexemplary embodiment. Referring to FIG. 17, the X-ray generator 1710 mayinclude an anode electrode 1712 that emits an X-ray due to collisionsbetween electrons emitted by a plurality of electron emission devices1711 that are independently driven. The anode electrode 1712 may have adifferent thickness with respect to a center axis P3 of the X-raygenerator 1710. For example, if the anode electrode 1712 is divided intothree regions, a thickness of the first region 1712 a increases as thefirst region 1712 a is closer to the center axis P3 of the X-raygenerator 1710, a thickness of a second region 1712 b is uniform, and athickness of a third region 1712 c decreases as the third region 1712 cis farther away from the center axis P3 of the X-ray generator 1710.Thus, an X-ray from the first region 1712 a is radiated to the object200 at the first radiation angle θ3, an X-ray from the second region1712 b may be vertically radiated to the object 200, and an X-ray fromthe third region 1712 c may be radiated to the object 200 at the secondradiation angle θ4.

If the electron emission device 1711 corresponding to the first region1712 a emits electrons at a first time, the X-ray generated in the firstregion 1712 a may be radiated to the object 200 at the first radiationangle θ3. If the electron emission device 1711 corresponding to thesecond region 1712 b emits electrons at a second time, the X-raygenerated in the second region 1712 b may be vertically radiated to theobject 200. If the electron emission device 1711 corresponding to thethird region 1712 c emits electrons at a third time, the X-ray may begenerated in the third region 1712 c. The X-ray generated in the thirdregion 1712 c may be radiated to the object 200 at the second radiationangle θ4. Thus, an X-ray imaging apparatus may perform X-ray imaging toacquire the tomography image by using a shape of the anode electrode1712.

The X-ray imaging to acquire the tomography image is performed threetimes. However, this is for convenience of description, and X-rayimaging may be performed two or more times to acquire the tomographyimage.

The X-ray imaging apparatus according to the present exemplaryembodiment may further include a sensor that senses the object 200. Thesensor may include a plurality of sensors. Each sensor may sense anexistence of the object 200 and determine a location of the object 200based on results of sensing by all the sensors. The sensors may be lightsensors, such as, illumination sensors, touch sensors, etc. Inparticular, when the sensors are touch sensors, the sensors may beformed as a single pad, i.e., a touch pad.

FIGS. 18A and 18B are schematic diagrams of X-ray generators 1810 a and1810 b including a plurality of sensors 1871 according to an exemplaryembodiment. The sensors 1871 may be arranged to be integrated with theX-ray generators 1810 a and 1810 b. Referring to FIG. 18A, a onedimensional sensor array 1870 is located at a side of the onedimensional X-ray generator 1810 a so that the one dimensional X-raygenerator 1810 a and the one dimensional sensor array 1870 may beintegrated. Alternatively, referring to FIG. 18B, the sensor 1871 may belocated to be spaced apart from each other on a second dimensional X-raygenerator 1810 b. The sensors 1871 may be located so as not to overlapwith X-ray sub-generators 1811. In FIG. 18B, the sensors 1871 arelocated on regions in which four X-ray sub-generators 1811 are adjacent.In particular, the sensors 1871 may be located on the same plane of theX-ray generators 1810 a and 1810 b as an anode electrode (not shown).Thus, the path of an emitted X-ray will not be influenced by the sensors1871. However, the present exemplary embodiment is not limited thereto.Locations of the sensors 1871 can vary so long as the X-ray travelingpath and the sensors 1871 do not overlap with each other.

Although the sensors 1871 are located throughout the entire region inwhich the X-ray generators 1810 a and 1810 b are located, the presentexemplary embodiment is not limited thereto. When a size and location ofan object is known, the sensors 1871 may not be located in a region in aregion in which there is no possibility that the object is to belocated. The sensors 1871 may be focused in a region corresponding to aboundary of the object. The sensors 1871 located on the X-ray generators1810 a and 1810 b may be light sensors.

Although the sensors 1871 are integrally formed with the X-raygenerators 1810 a and 1810 b in FIGS. 18A and 18B, the present exemplaryembodiment is not limited thereto. The sensors 1871 may be integrallyformed with X-ray detectors. For example, when X-ray detectors are onedimensional X-ray detectors, the sensors 1871 may be located to contactthe X-ray detectors. When the X-ray detectors are second dimensionalX-ray detectors, the sensors 1871 may be located between the X-raydetectors.

FIGS. 19A and 19B illustrate a panel 1932 on which sensors 1971 arelocated according to an exemplary embodiment. Referring to FIG. 19A, thesensors 1971 may be located on the panel 1932. If the sensors 1971 arelocated on an X-ray generator, when the X-ray generator does not coveran object, the X-ray generator needs to be moved in a horizontaldirection to detect a location of the object. However, since the panel1932 covers the object, when the sensors 1971 are located on the panel1932, the object may be more easily detected. The sensors 1971 may belocated on a surface of the panel 1932 facing the X-ray generator or ona surface of the panel 1932 facing the object. The sensors 1971 locatedon the panel 1932 may be light sensors, touch sensors, etc. When thesensors 1971 are located on the panel 1932, the sensors 1971 may beformed of a transparent material so as to minimize the diffusion of anX-ray or to minimize absorption by the sensors 1971. In particular, whenthe sensors 1971 are touch sensors, the sensors 1971 may be implementedas a touch pad 1980.

FIG. 20 is a block diagram of the X-ray imaging apparatus 100 of FIG. 1according to an exemplary embodiment. Referring to FIG. 20, the X-rayimaging apparatus 100 may include an X-ray generator 10, an X-raydetector 20, the user input device 52, a display 54, a processor 56, anda controller 60. The X-ray imaging apparatus 100 may further include asensor 70 that senses an object.

The X-ray generator 10 radiates an appropriate X-ray to the object asdescribed above. The X-ray generator 10 is described above, and thus adescription thereof will not be repeated here. The X-ray detector 20detects the X-ray that transmitted the object. When the X-ray generator10 radiates the X-ray, the X-ray detector 20 detects the X-ray thattransmitted to the object, which is described above, and thus adescription thereof will not be repeated here.

The user input device 52 receives an input of an X-ray imaging commandfrom a user, such as a medical expert. Information regarding a commandto change a location of the X-ray generator 10, a parameter adjustmentcommand to vary an X-ray spectrum, a command regarding a main body ofthe X-ray imaging apparatus 100 or a movement of the X-ray generator 10,and all commands received from the user is transmitted to the controller60. The controller 60 controls elements included in the X-ray imagingapparatus 100 according to a user command.

The processor 56 receives an electrical signal corresponding to theX-ray detected by the X-ray detector 20. The processor 56 may preprocessthe electrical signal to acquire an image. In this regard, preprocessingmay include at least one of offset compensation, algebra conversion,X-ray dose compensation, sensitivity compensation, and beam hardening.The image includes a tomography image.

The processor 56 may preprocess the electrical signal corresponding tothe detected X-ray to acquire the image. The processor 56 may preprocessan electrical signal corresponding to the detected X-ray to acquiretransparent data and reconfigure the acquired transparent data for eachradiation angle to acquire the tomography image.

A location and a type of the sensor 70 are described above, and thus adetailed description thereof will not be repeated here. Each sensorincluded in the sensor 70 may sense an existence of the object and applya result of the sensing to the controller 60. Thus, the controller 60may determine a location of the object by using results of the sensingby the sensors. The controller 60 may control the X-ray generator 10 toallow an X-ray sub-generator of the X-ray generator 10 corresponding tothe location of the object to generate an X-ray. Furthermore, thecontroller 60 may control the X-ray detector 20 to allow an X-raysub-detector of the X-ray detector 20 corresponding to the location ofthe object to detect an X-ray that is transmitted to the object.

In an exemplary embodiment, only some of the X-ray sub-generatorsoperate to image the object, thereby reducing an X-ray radiation dose.Furthermore, only some of the X-ray sub-detectors operate, and thus alifetime of the X-ray detector 20 may be increased, thereby simplifyingsignal processing.

An X-ray imaging method using the sensor 70 will now be described. FIG.21 is a flowchart of an X-ray imaging method according to an exemplaryembodiment. Referring to FIG. 21, the sensor 70 senses the object 200(operation S2110). If the object 200 is located between the first panel32 and the second panel 34 of the X-ray imaging apparatus 100 of FIG. 1,the X-ray imaging apparatus 100 may move at least one of the first panel32 and the second panel 34 according to a user command to compress theobject 200. If the object 200 contacts the first panel 32 and the secondpanel 34 or is pressed by the first panel 32 and the second panel 34,each sensor included in the sensor 70 may sense an existence of theobject 200. For example, when sensors are illumination sensors, thesensors may sense whether the object 200 exists based on an illuminationchange, and when the sensors are touch sensors, the sensors may sensewhether the object 200 exists according to whether the touch sensors aretouched. A result of the sensing by each sensor is applied to thecontroller 60.

The controller 60 may control the X-ray generator 10 to allow an X-raysub-generator of the X-ray generator 10 corresponding to a location ofthe object 200 to generate an X-ray by using results of the sensing bythe sensor 70 (operation S2120). The controller 60 may determine thelocation of the object 200 from the result of the sensing by eachsensor. For example, the location of the object 200 may be determinedfrom locations of the sensors that detect the illumination change andwhether the sensors are touched. The location of the object 200 may bedetermined to be slightly greater than locations of the sensors. Thecontroller 60 may control the X-ray sub-generator of the X-ray generator10 corresponding to the location of the object 200 to generate theX-ray. An X-ray generation method may vary according to sizes of anX-ray test area and an X-ray generation area, and according to whetheran image that is to be imaged is a simple image or a tomography image.

The controller 60 may control the X-ray detector 20 to allow an X-raysub-detector of the X-ray detector 20 corresponding to the location ofthe object to detect the X-ray (operation S2130). An X-ray detectionmethod may vary according to sizes of the X-ray test area and the X-raygeneration area, and according to whether the image that is to be imagedis the simple image or the tomography image. This is described above,and thus a detailed description thereof will not be repeated here. Ifonly the X-ray sub-detector of the X-ray detector 20 corresponding tothe location of the object detects the X-ray, the X-ray diffused bybeing transmitted to the object 200 is detected, thereby blocking noise.

Then, the processor 56 may receive an electrical signal corresponding tothe X-ray detected by the X-ray sub-detector to acquire an image(operation S2140). The acquired image may be displayed on the display54.

Although the sensor 70 senses the object 200, and the X-ray imagingapparatus 100 operates according to a result of the sensing, the presentexemplary embodiment is not limited thereto. When the sensor 70 is notincluded in the X-ray imaging apparatus 100, the X-ray imaging apparatus100 may perform imaging as described with reference to FIGS. 11A through15C.

It should be understood that the exemplary embodiments described hereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each exemplaryembodiment should typically be considered as available for other similarfeatures or aspects in other exemplary embodiments.

While one or more exemplary embodiments have been described withreference to the figures, it will be understood by those of ordinaryskill in the art that various changes in form and details may be madetherein without departing from the spirit and scope as defined by thefollowing claims.

What is claimed is:
 1. An X-ray imaging apparatus comprising: a firstpanel configured to contact an object; an X-ray generator configured tomaintain a uniform distance with the first panel and configured togenerate an X-ray and transmit the X-ray to the object; a second panelfacing the first panel and configured to contact the object; and anX-ray detector configured to detect the X-ray transmitted by the X-raygenerator to the object.
 2. The X-ray imaging apparatus of claim 1,wherein the X-ray generator is configured to move towards or away fromthe object.
 3. The X-ray imaging apparatus of claim 1, wherein a firstsurface of the first panel is configured to contact the object and asecond surface of the first panel facing the first surface is configuredto contact the X-ray generator.
 4. The X-ray imaging apparatus of claim1, wherein the X-ray generator and the first panel are integrated. 5.The X-ray imaging apparatus of claim 1, wherein a first surface of thesecond panel is configured to contact the object and a second surface ofthe second panel facing the first surface is configured to contact theX-ray detector.
 6. The X-ray imaging apparatus of claim 1, wherein atleast one of the first panel and the second panel presses the object. 7.The X-ray imaging apparatus of claim 1, wherein, when an X-raygeneration area of the X-ray generator is smaller than a test area ofthe object, the X-ray generator is configured to move so as to transmitan X-ray to an entire test area of the object.
 8. The X-ray imagingapparatus of claim 7, wherein the X-ray generator is configured toradiate the X-ray in a first area of the object and configured to moveso as to radiate the X-ray in a second area of the object.
 9. The X-rayimaging apparatus of claim 1, wherein the X-ray generator is configuredto move horizontally along the first panel.
 10. The X-ray imagingapparatus of claim 1, wherein, when an X-ray detection area of the X-raydetector is smaller than a test area of the object, the X-ray detectoris configured to move so as to detect an X-ray transmitted to an entiretest area of the object.
 11. The X-ray imaging apparatus of claim 10,wherein the X-ray detector is configured to detect the X-ray transmittedto a first area of the object and is configured to move so as to detectthe X-ray transmitted to a second area of the object.
 12. The X-rayimaging apparatus of claim 10, wherein the X-ray detector is configuredto move horizontally along the second panel.
 13. The X-ray imagingapparatus of claim 1, further comprising: a gantry wherein the gantrycomprises the first panel, the X-ray generator, the second panel, andthe X-ray detector.
 14. The X-ray imaging apparatus of claim 1, whereinthe X-ray generator comprises a plurality of X-ray sub-generators whichare arranged in one dimension or in two dimensions.
 15. The X-rayimaging apparatus of claim 1, wherein the X-ray generator is configuredto change a radiation angle of an X-ray transmission according to alocation of the object.
 16. The X-ray imaging apparatus of claim 1,further comprising: a sensor configured to sense the object, wherein apartial region of the X-ray generator corresponding to a location of theobject generates the X-ray.
 17. An X-ray imaging method comprising:pressing an object located between a first panel and a second panel byusing at least one of the first panel and the second panel; generatingan X-ray by an X-ray generator located a uniform distance from the firstpanel; transmitting by the X-ray generator the generated X-ray to theobject; and detecting by an X-ray detector the X-ray transmitted to theobject.
 18. The X-ray imaging method of claim 17, wherein the X-raygenerator is configured to move towards and away from the object. 19.The X-ray imaging method of claim 17, wherein, when an X-ray generationarea of the X-ray generator is smaller than a test area of the object,the X-ray generator is configured to move along the first panel toradiate an X-ray in the entire test area of the object.
 20. The X-rayimaging method of claim 17, wherein, when an X-ray detection area of theX-ray detector is smaller than a test area of the object, the X-raydetector is configured to move along the second panel to detect an X-raytransmitted to the entire test area of the object.